Thank you to the photographers of the following photos, who allowed us to use their images in our promotional material by making their images available under Creative Commons, license http://creativecommons.org/licenses/by-sa/2.0/deed.en:

http://www.flickr.com/photos/boonlee89/6429572683/
http://www.flickr.com/photos/haynes/1212538765/
http://www.flickr.com/photos/fortherock/3930972474/
http://www.flickr.com/photos/31274030@N08/4093311021/
http://www.flickr.com/photos/7701055@N05/6567297279/
http://www.flickr.com/photos/london/53477863/
http://www.flickr.com/photos/bochalla/4532668606/
http://www.flickr.com/photos/boonlee89/6429572683/
http://www.flickr.com/photos/zenat_el3ain/3965420333/
http://www.flickr.com/photos/giovannijl-s_photohut/465718522/
http://www.flickr.com/photos/83183993@N00/464950032
http://www.flickr.com/photos/ejcallow/4589440686/
http://www.flickr.com/photos/75960772@N03/6969066731/
http://www.flickr.com/photos/16822508@N05/2081102403
http://www.flickr.com/photos/58782227@N00/3807521033
http://www.flickr.com/photos/bobaliciouslondon/5248877223/
http://www.flickr.com/photos/16782093@N03/3808446391/
http://www.flickr.com/photos/flatworldsedge/5092591483/
http://www.flickr.com/photos/saphirai/2403730180/
http://www.flickr.com/photos/pedrosz/2115782565/
http://www.flickr.com/photos/ru_boff/3318548951/
http://www.flickr.com/photos/borkurdotnet/363680609/
http://www.flickr.com/photos/mauro9/5068223866/
http://www.flickr.com/photos/24736216@N07/7109374635/
http://www.flickr.com/photos/rnugraha/2003147365/
http://www.flickr.com/photos/mariosp/7273774420/
http://www.flickr.com/photos/marcveraart/2759520258/